In modern fabricated structural assemblies, designed for optimum strength-to-weight ratios, as required by today's aerospace and other non-related industries comprising one or more threaded fastening systems, in which the residual axial tension to be retained within a threaded fastening systems bolt after installation, approaches close to 80% of that bolts ultimate tensil failure, it is of great importance, to be able to measure the exact torque applied to that threaded fastening system under installation, as well as to implement a failsafe means for terminating either that fastening systems bolts or nuts rotation, at the precise moment when either that bolt or nut has attained a predetermined value of torque. Even the most experienced installation operator, using only his own discretion and manual dexterity, cannot determine the proper value of torque necessary to obtain a fastening system's optimum performance.
To assign the determination of what constitutes sufficient torque, for the attainment of a threaded fastening system's optimum performance, to an installation operation depending on its own discretion and manual dexterity alone, is not advisable.
Therefore, in order to eliminate costly rejects and to prevent possible failure of structural assemblies and equipment in which the use of threaded fastening systems are prevalent, and since the use of softer materials such as aluminum and plastics are more and more accepted throughout the industries and the employment of unqualified labor rises, it becomes apparent that the precision for repeatability of a threaded fastener system under installation, must be dictated by the proper presetting, within a threaded fastening system's installation tool, thereby releaving the installation operator from his own discretion during installation.